The author had two years of experience, during which he saw things that surprised him. He didn't say he was a know-it-all or that others taught badly. He wasn't

The author had two years of experience, during which he saw things that surprised him. He didn't say he was a know-it-all or that others taught badly. He wasn't very satisfied with his own results. He decided to try something different. I have not seen arrogance.